• Toxicological Research
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• v.27 no.1
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• pp.31-36
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• 2011

The methanol extract of 12 medicinal plants were evaluated for its antibacterial activity against Gram-positive (5 strains) and Gram-negative bacteria (10 strains) by assay for minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC). The antibacterial activity was determined by an agar dilution method (according to the guidelines of Clinical and Laboratory Standard Institute). All the compounds (12 extracts) of the 8 medicinal plants (leaf or root) were active against both Gram-negative and Gram-positive bacteria. Gram-negative showed a more potent action than Gram positive bacteria. The MIC concentrations were various ranged from $0.6\;{\mu}g/ml$ to $5000\;{\mu}g/ml$. The lowest MIC ($0.6\;{\mu}g/ml$) and MBC ($1.22\;{\mu}g/ml$) values were obtained with extract on 4 and 3 of the 15 microorganisms tested, respectively.

• Biomedical Science Letters
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• v.29 no.2
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• pp.88-94
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• 2023

In oriental medicine, the fruit of Actinidia polygama has long been used to alleviate the symptoms of gout, arthritis, and inflammation. In this study, it was to designed to analyze the antibacterial activity of A. polygama ethanol extract (APEE) against Streptococcus mutans, one of the major strains for dental caries, and Porphyromonas gingivalis, one of the critical strains for periodontal disease. The antibacterial activity of APEE was analyzed by disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. In addition, it was also analyzed the inhibitory effect of APEE on bacterial growth and biofilm formation against both oral pathogens. APEE exhibited its antibacterial effect through the inhibited bacterial diffusion as well as low concentration of MIC and MBC. In addition, APEE significantly inhibited not only bacterial growth but also biofilm formation in a dose-dependent manner. Consequently, APEE showed potent antibacterial activity against both S. mutans and P. gingivalis, which indicates that APEE might be used as a potential antibacterial material for the improvement of oral healthcare.

• Korean journal of food and cookery science
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• v.26 no.2
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• pp.206-213
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• 2010

In this study, the antibacterial activities of essential oil from Zanthoxylum schinifolium against four Gram-positive bacteria and six Gram-negative bacteria were investigated. The antibacterial activity of the oils was determined using the agar-well diffusion assay, MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration). In particular, essential oil from Z. schinifolium showed higher antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria. Essential oil from Z. schinifolium displayed large inhibition zones especially against Bacillus cereus (31 mm). At concentrations between 0 and $20\;{\mu}g/mL$ the oils showed an antibacterial effect against both Gram-negative and Gram-positive bacteria. The minimum inhibitory concentration (MIC) values against nine bacteria ranged from 1.25 to $5\;{\mu}g/mL$. The minimum bactericidal concentration (MBC) values against eight bacterial ranged from 2.5 to $20\;{\mu}g/mL$, except Shigella sonnei. Furthermore, our finding on the antibacterial activities of essential oils from Zanthoxylum schinifolium validated the use of this plant for medical purposes.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.297-301
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• 2013

The present study was to investigate anti-microbial effects of curcumin on major bacterial pathogens for farmed fish, such as Aeromonas hydrophila, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida, Edwardsiella tarda, Vibrio vulnificus, V. paraheamolyticus using disk diffusion, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) tests. In disc diffusion test, curcumin exhibited concentration-dependent antimicrobial activities to all bacteria pathogens used in the study. Antimicrobial effects of curcumin was found differently depending on bacterial species when determined by MIC or MBC tests. For examples, E. tarda and A. hydrophila was respectively the most sensitive bacterium for bacteriostatic and bacteriocidal effect of curcumin. Collectively, curcumin could be a potential natural drug for controlling pathogenic bacteria in the aquaculture industry.

• Journal of Pharmacopuncture
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• v.22 no.1
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• pp.49-54
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• 2019

Objective: Antibiotic resistance is a global health problem and threatens health of societies. These problems have led to a search for alternative approaches such as combination therapy. The aim of the present study was to investigate the effect of caffeine and omeprazole in combination with gentamicin or ciprofloxacin against standard and clinically resistant isolates of Staphylococcus aureus and Escherichia coli. Methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values of different agents against bacterial strains were determined. The interaction of non- antibiotic drugs with gentamicin and ciprofloxacin was studied in vitro using a checkerboard method and calculating fraction inhibitory concentration index (FICI). Verapamil as efflux pump inhibitor was used to evaluate the possible mechanism of bacterial resistance to antibiotics. Results: The MIC and MBC values of gentamicin against bacterial strains were in the range of $20-80{\mu}g/ml$ and $40-200{\mu}g/ml$, respectively. Caffeine and omeprazole had no intrinsic inhibitory activity against tested microorganisms. However, upon combination of caffeine with antibiotics, the synergistic effects were observed. Verapamil was able to reduce the MIC values of gentamicin (4 folds) only in some bacterial strains. Conclusion: These findings indicated that caffeine was effective in removing bacterial infection caused by S. aureus and E. coli. The relevant mechanisms of antibiotic resistance were not related to the drug efflux.

• Korean Journal of Veterinary Service
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• v.38 no.2
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• pp.65-70
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• 2015

The present study was to investigate in vitro antimicrobial effects of propolis against six different fish bacterial pathogens, Aeromonas hydrophila, Edwardsiella tarda, Vibrio vulnificus, V. parahaemolyticus, A. salmonicida subsp. masoucida, A. salmonicida subsp. salmonicida) using minimum inhibitory concentration (MIC) and minimum bacteriocidal concentration (MBC) tests. In the results, propolis exhibited antimicrobial activity against all bacteria used in the present study, but there was no marked difference in bacterial species except Vibrio species. Collectively, propolis was thought to be an usefulness antimicrobial substance for controlling bacterial diseases in the fish industry.

• Journal of the Korea Society of Computer and Information
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• v.21 no.5
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• pp.135-139
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• 2016

Scrophularia ningpoensis hemsl has been traditionally used in China and Vietnam for treatment of bacteria, atopy, pimple, tonsillitis, angina and encephalitis for a long time. The main objectives of this study were to evaluate the antibacterial activity of the Scrophularia ningpoensis hemsl extract on biofilm formation of Klebsiella pneumoniae. Antibacterial activity was conducted using disc diffusion assay and minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) were determined using the broth micro dilution method in accordance to Clinical and Laboratory Standards Institute guidelines(CLSI). Furthermore, cytotoxicity on L929 were assessed using animal cell culture for the proliferation test(MTT cell assay) and the biofilm forming capacity of the K. pneumoniae were determined using the colony forming unit (CFU) assay. The extract exhibited considerable antibacterial activity. K. pneumoniae was susceptible to the extract with the MIC and MBC of 0.1875 and $1.5mg/m{\ell}$ respectively. Cytoxicity test in L929 showed no sign of toxicity at the concentration of $0.75mg/m{\ell}$ and at the same concentration the extract caused inhibition of bacterial biofilm formation. The extract of Scrophularia ningpoensis hemsl possesses an in vitro antibacterial antibiofilm activities against K. pneumoniae, with no sign of cytoxicity on L929.

• Korean Journal of Veterinary Research
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• v.56 no.2
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• pp.103-108
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• 2016

Salmonellosis is a major bacterial zoonosis that causes self-limited enteritis in animals and foodborne disease and typhoid fever in humans. Recently, multi-drug-resistant strains of Salmonella spp. have increased and caused more serious problems in public health. The present study investigated the antibacterial effects of egg-white lysozyme (EWL) against Salmonella (S.) Typhimurium and the therapeutic effects of EWL for murine salmonellosis. Evaluation of the antibacterial effects of EWL against S. Typhimurium revealed a minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of EWL of 6.25 and $300{\mu}g/mL$, respectively. In the bacterial growth inhibition test, EWL at 300 (p < 0.05) and $600{\mu}g/mL$ (p < 0.01) significantly inhibited the growth of S. Typhimurium at 4 h post-incubation. EWL administration at MIC (LYS-1), MBC (LYS-2) and $2{\times}MBC$ (LYS-3) for 14 days resulted in mortality of mice infected with S. Typhimurium of 70, 40 and 10%, respectively, while that of control mice (CON) was 90%. Counts of S. Typhimurium in murine spleens were significantly lower in LYS-2 and LYS-3 than CON (p < 0.05). The results of this study indicate that EWL has the potential for treatment of ICR mice infected with S. Typhimurium.

• Journal of Life Science
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• v.27 no.6
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• pp.611-616
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• 2017

The antibacterial activities of nine oriental herbal medicine extracts were measured against seven kinds of bacteria known to cause food poisoning and disease. The extracts were prepared with distilled water using an autoclave ($121^{\circ}C$ for 30 min). The extraction yields of nine oriental herbal medicines were in the rage of 0.5%-33.4%. The antibacterial activities were evaluated using the paper-disc method. Extracts of Hwangryeon, Jiyu, and Ohbaeja showed antibacterial activities while the others did not. Extracts of Coptis japonica, Hwangryeon, and Sanguisorba officinalis, Jiyu showed antibacterial activities only against Clostridium perfringens and Listeria monocytogenes. Extracts of Rhus javanica, Ohbaeja showed the strongest antibacterial activities against all the bacteria tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of R. javanica extracts were in the range of 2.4~20 mg/ml for the bacteria tested. In conclusion, the extract of R. javanica showed superior antibacterial activities against the seven bacterial strains tested. The MIC and MBC values for each bacterium were represented as strain names (MIC, MBC), which were Bacillus cereus (11.2, 20), Clostridium perfringens (2.4, 4.7), Escherichia coli (9.1, 9.1), Listeria monocytogenes (11.1, 20), Salmonella typhi (4.7, 9.1), Staphylococcus aureus (2.4, 4.7), and Vibrio parahaemolyticus (2.4, 5.3). Further purification and study of this antibacterial material would be helpful for developing antibiotics or promoting synergistic effects with known antibiotics, producing antibacterial material for lengthening the shelf-life of food, and so on.

• Biomedical Science Letters
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• v.29 no.3
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• pp.130-136
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• 2023

In this study, the anti-bacterial activity of three medicinal herbs such as Dioscorea batatas, Morus alba, and Tagetes erecta, have been applied in oriental medicine against Escherichia coli and Staphylococcus aureus. The antibacterial activity of Dioscorea batatas ethanol extract (DBEE), Morus alba ethanol extract (MAEE), and Tagetes erecta ethanol extract (TEEE) was analyzed by disk diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays. As a result, three medicinal herbs exhibited antibacterial activity in a dose-dependent manner as well as MAEE and TEEE showed the most potent antibacterial activity followed by disk diffusion assay against E. coli and S. aureus, respectively. MIC against E. coli and S. aureus was 1.6 mg/mL of MAEE and TEEE as well as 0.2 mg/mL of TEEE. MBC against both strains was 5 mg/mL of DBEE and 2.5 mg/mL of TEEE. Consequently, three medicinal herbs in this study showed potent antibacterial activity through the inhibited growth of E. coli and S. aureus, which is considered as a potential candidate for cosmeceutic agents to attenuate the pruritus. In addition, antibacterial and antihistamine effects followed by the extraction solvents should be analyzed in future studies.